30 FLORA OF THE YELLOWSTONE NATIONAL PARK. 



Arenaria biflora, var. obtusa.Watson (A. arctica, Stev. of Hayd. Rep. for 1871-72). 

 Common on alpine summits. Mt. Holmes, 10,000 ft. alt.; Saddle Mt., 

 10,200 ft. alt.; "High peaks near Yellowstone Lake" (Coulter); Red 

 Mt., 10,000 ft. alt. (Adams). 



Arenaria stricta, Watson. 



Mt. Washbume, 9800 ft. alt.; Mt. Norris, 9000 ft. alt. Not common. 



Arenaria lateriflora, L. 



Grassy slopes, Slough and Pebble Creeks, 6500-8000 ft. alt. Rare. 



Sagina Linnaei, Presl. 



Rather common in wet places at middle elevations. Fawn Creek, 

 7400 ft. alt.; Lower Geyser Basin (Coulter); Mud Springs (Adams). 



PORTULACACE^. 



Calandrinia pygmaea, Gray. 



Generally on bare wet subalpine and alpine slopes. Mt. Holmes, 9300 

 ft, alt.; Sepulchre Mt., 8200 ft. alt.; Red Mt., 10,000 ft. alt., and Tower 

 Falls, 6500 ft. alt. (Coulter). 



Claytonia Chamissonis, Esch. 



Gibbon Lake, 8000 ft. alt.; East Fork of the Yellowstone, 6500 ft. 

 alt.; Yellowstone Lake (Coulter, Adams); Lower Falls of the Yellow- 

 stone (Coulter). 



Claytonia Caroliniana, Michx., var. sessilifolia, Torr. 

 Common in wet places from 7000-9500 ft. alt. 



Spraguea umbellata, Torr. 



Common in dry and rocky places, especially on hot spring and geyser 

 formation, from 6500 to 8500 ft. alt. 



Lewisia rediviva, Pursh. 



Mammoth Hot Springs, 6200 ft. alt. ; Yellowstone Lake (Adams). 

 Rare within the Park limits. 



ELATINACE^. 



Elatine triandra, Sclikulir. 



Bottom of ponds at outlet of Yellowstone Lake with Isoetes Bolanderi 

 and Subularia aquatica. 



Elatine Americana, Arn. (Trimerous form). 



Muddy shore of ponds at outlet of Yellow stone Lake, with Limosella 

 aquatica and Tilht^a aiKjuatifoUa. 



